Salt platform

ABSTRACT

A grid ( 250, 280 ) is disclosed which can be used as part of a salt platform ( 10, 50, 80 ) to support salt in an ion exchange water softener. The grid is preferably formed of ABS plastic and has a border portion ( 252 ) and bands ( 254, 256 ) without holes ( 274 ) formed therethrough for strength. When the grid is used as part of a salt platform having vertically oriented members ( 12-24 ) with open upper ends, cap portions ( 258-270 ), without holes formed therethrough, are used to cover the upper ends of the members. A ring ( 350 ) can be used to fit the salt grid in the brine tank.

This application is a division of application Ser. No. 08/594,245, filedon Jan. 30, 1996, now U.S. Pat. No. 5,788,933, which is aContinuation-In-Part (CIP) of application Ser. No. 08/450,896, filed onMay 26, 1995, now U.S. Pat. No. 5,643,541, which is aContinuation-In-Part (CIP) of application Ser. No. 08/432,728, filed onMay 2, 1995, now abandoned.

TECHNICAL FIELD OF THE INVENTION

This invention relates to water softeners using salt, and in particularto a platform for supporting the salt.

BACKGROUND OF THE INVENTION

Water softeners find wide applications throughout society. In manyapplications, it is desirable to soften the water by removing thehardness minerals from the water before use. This is particularlycritical in boiler operation where use of hard water will create boilerscale and rapidly reduce operating efficiencies.

A common water softening process is to use water softeners designed forthis purpose. Water softening tanks contain cation exchange resincapable of exchanging hardness ions, i.e., calcium and magnesium forsodium ions which are very soluble.

When the hardness exchanging capacity of the water softening resin hasexhausted it stops producing soft water. It then becomes necessary toregenerate the resin with a saturated solution of sodium or potassiumchloride. Because of cost, sodium chloride is usually the chemical ofchoice.

Sodium chloride brine solution is made in a separate tank built anddesigned for this purpose, and this tank is called a brine tank.

Modern water softeners are well engineered and designed to produce softwater with all regeneration actions done automatically, including thetransfer of the saturated brine from the brine tank to the watersoftener tanks.

In order for the water softener resin to be properly rejuvenated, thesaturated brine solution must be of high quality and a measured volumemust be delivered whenever needed.

A properly designed and engineered brine tank will provide these needsby delivering a measured quantity of saturated salt brine containing afixed amount of dissolved salt per gallon of water.

This is accomplished by using a horizontal salt grid in a vertical tank.The height and diameter of the salt grid varies for each softeningsystem, depending on many factors, but in all cases the height of thesalt grid sets the volume of water in the brine tank.

In actual practice, the brine system is set to fill the brine tank withfresh water from the bottom of the tank to approximately 1″ above thesalt grid and then shut off.

Using this method, only 1″ of water touches the vertical salt pile,which may be several hundred pounds in weight, stored on top of the saltgrid.

This system is called a dry salt shelf system, as opposed to a wet saltbrine tank system where most or all the salt is immersed in water. Thedry salt shelf system has significant advantages over the wet saltsystem. The dry salt shelf method produces 100% saturated brine(specific gravity 1.2) all the time where wet salt methods do not. Thedry salt shelf system affects more dry salt storage in the same sizebrine tank than a wet salt system. A dry salt shelf system is easier tokeep clean than the wet salt system. A dry salt shelf system does notrequire a gravel support bed at the bottom of the brine tank. The drysalt shelf system offers lower maintenance costs to the operator, nogravel cleaning or replacement.

The dry salt shelf system has no messy brine float valves as used abovethe liquid brine on wet salt systems. These float valves become corrodedwith salt creep and require repair and/or replacement frequently. Thedry salt shelf system uses brine float or refill valves in the lowersection of the brine tank (below the shelf) and are less exposed to therisk of malfunctions or corrosion, thus operating more efficiently. Thedry salt shelf system uses all of the salt stored before the brine tankneeds to be refilled. Liquid below the shelf is saturated brine even ifonly one grain of salt remains on the shelf. The brine tank salt refillis less often with the dry salt shelf system because of the greater saltstorage capacity it offers. Brine tank corrosion is reduced oreliminated on steel brine tanks with the dry salt shelf system becausethe liquid level is down below the dry salt, thus less air/brineexposure. The dry salt shelf system allows more programmed salt deliveryscheduling because the salt stored is easily seen and thus the quantityremaining can be easily determined. The dry salt shelf system allows theuse of all grades of salt, even the most economical rock type salt. Thedry salt shelf type brine system can be cleaned in less than one hour,regardless of size whereas a wet salt tank may take one day and requirethe water softener to be down.

Dissolving of salt starts immediately and continues until the volume ofwater beneath the salt grid becomes saturated with dissolved salt. Whensaturation occurs, dissolving ceases. Stored salt above the salt gridnot in contact with the water remains dry, preventing bridging andmushing.

Using a salt grid enables an engineer to calculate the quantity andquality of a particular size brine tank will produce. The engineer thenis able to select the proper brine tank for the water softener system.It is imperative that the grid and support system be strong to supportthe mass of weight placed upon it. Until now, salt grids and supportsystems have usually been made from pegboard. It is readily availableand cheap; however, in contact with the salt brine it tends to deform,warp and those portions of the salt grid left unsupported tend to breakand collapse, dumping the salt stored on them down into the brinemeasuring area.

When this occurs, it causes the water softener to malfunction.

The salt grid and support system must be rebuilt, and in time it failsagain.

For these reasons, the salt grid and support system could not be used inlarger brine tanks.

As the demand increased for larger and larger water softeners, thedemand for more saturated brine increased.

In order to provide this requirement, brine tanks increased in size andthe pegboard salt grid and support system could not be used as they werenot strong enough to hold the weight.

These larger systems were forced to use the less efficient older methodof wet storage.

This method consists of loading the brine tank with several hundredpounds of gravel on the bottom. Several hundred pounds of salt is thenpoured upon the gravel and water is then added until a portion or all ofthe salt is submerged.

The measuring advantage of the salt grid system is lost.

The salt brine produced by the wet salt storage method is often of poorquality and submerged salt tends to bridge and mush, causing maintenanceproblems.

The salt grid plate and support system we have designed and built isstrong enough that it may be used in the larger systems.

Again, the engineer can calculate the exact quantity of brine needed byutilizing the salt grid method.

SUMMARY OF THE INVENTION

In accordance with one aspect of the present invention, an improved saltplatform grid is provided which is formed of ABS plastic. The grid iscircular and has a border about the outer rim thereof and at least oneband extending from the outer rim through the center of the grid. Aplurality of holes are formed through the grid between the border andthe band.

In accordance with another aspect of the present invention, the grid isformed with dual bands, intersecting at the center of the grid at a 90°angle. In accordance with another aspect, the grid is formed with a wellopening therein.

In accordance with another aspect of the present invention, a saltplatform is provided in which the grid is used. The platform includes aplurality of vertically oriented members with upper ends, the upper endsof the vertically oriented members being open. The grid has coverportions sized to cover the open upper ends of the vertically orientedmembers when the grid is set atop the upper ends of the verticallyoriented members, none of the holes being formed through the coverportions.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention and theadvantages thereof, reference is now made to the following descriptiontaken in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view of a salt platform forming a firstembodiment of the present invention;

FIG. 2 is a top view of the salt platform;

FIG. 3 is a bottom view of the salt platform;

FIG. 4 is a side view of the salt platform;

FIG. 5 is another side view of the salt platform taken from an angledifferent than FIG. 4;

FIG. 6 is a perspective view of a salt platform forming a secondembodiment of the present invention;

FIG. 7 is a top view of the salt platform of FIG. 6;

FIG. 8 is a bottom view of the salt platform of FIG. 6;

FIG. 9 is a side view of the salt platform of FIG. 6;

FIG. 10 is another side view of the salt platform of FIG. 6 taken froman angle different than FIG. 9;

FIG. 11 is a schematic view of a third embodiment of the presentinvention;

FIG. 12 is a perspective view of a fourth embodiment of the presentinvention;

FIG. 13 is a side view of the embodiment of FIG. 12;

FIG. 14 is a top view of the embodiment of FIG. 12;

FIG. 15 is a perspective view of a fifth embodiment of the presentinvention with slotted sheets;

FIG. 16 is an exploded view of the embodiment of FIG. 15;

FIG. 17 is a plan view of an improved salt grid for use with the saltplatform of the present invention;

FIG. 18 is a plan view of an improved salt grid for use with the saltplatform forming the first embodiment of the present invention;

FIG. 19 is a side view of the improved salt grid;

FIG. 20 is a perspective view of a modification of the fourth embodimentof the present invention;

FIG. 21 is a vertical cross-sectional view of the embodiment of FIG. 20;

FIG. 22 is a plan view of the embodiment of FIG. 20;

FIG. 23 is a detail view of the additional support for the salt grid;

FIG. 24 is a plan view of a salt grid ring; and

FIG. 25 is a vertical cross-sectional view of the ring taken along line25—25 in FIG. 24.

DETAILED DESCRIPTION

With reference now to the accompanying drawings, wherein like orcorresponding parts are designated by the same reference numeral, andwith specific reference to FIGS. 1-5, a salt platform 10 is disclosedwhich forms a first embodiment of the present invention. The platformwill be positioned within a tank containing salt which forms part of awater softener. Frequently, the tank is a stand alone unit whichcontains only the salt and the platform. Water is then circulatedthrough the tank where sodium chloride is dissolved to substitute forthe minerals in the water.

The salt platform 10 can be seen to include a central verticallyoriented cylinder 12 and a series of radial vertically orientedcylinders 14-24. Each of the radially oriented cylinders is attached tothe central cylinder by a pair of horizontal bracing members 26 and 28.In the preferred embodiment, the cylinders and bracing members areformed of PVC plastic. The cylinder 12 can be 6 inches in diameter andthe cylinders 14-24 4 inches in diameter. The bracing members arepreferably glued to the cylinders with a commonly available PVC gluesuch as used in plumbing to join PVC pipe sections together.

The upper end 30 of each of the cylinders can be seen to lie in a commonplane 32. A grid 34 is preferably supported on the upper ends of each ofthe cylinders which, in turn, is in direct contact with the saltsupported by the platform. Preferably the grid 34 has a plurality ofapertures 36 formed therethrough for easy passage of the water throughthe salt. In the preferred embodiment, the grid is made out of ABSplastic and is one-quarter inch thick. The grid is cut to a diameterslightly less than the diameter of the tank in which the platform isused. A sufficient number of apertures are then formed through the gridto provide the necessary path for water flow. The apertures can be ⅛″ or¼″, for example. In one technique, a common sheet of perforated pegboard can be laid on top of the grid and used as a pattern to drill theholes through the grid. Clearly, the grid can be molded with the holesin place if this is more economical.

By using a plurality of vertically oriented cylinders, interconnected bybracing members, the load of salt is uniformly supported. It is commonfor water softeners to employ hundreds of pounds of salt and theplatform must be sufficiently strong to support this weight. Because aplurality of vertically oriented members are used, the invention workswell regardless of the specific platform height or width that is used.In order to uniformly support the entire weight bearing surface of thesalt grid, all of the area which is beneath the salt grid to the bottomof the tank and the sidewall to sidewall is used to support the grid bysuitable placement of the vertically oriented members and the horizontalbracing members. The salt platform can be used in tanks having adiameter range of between 18″ and 72″, for example. Moreover, the tanksneed not be cylindrical, but can have a square or other cross-section.

Each of the vertically oriented cylinders has a series of holes 49formed through the wall of the cylinders distributed along its length.These holes 49 allow water to fill the interior of the cylindersrelatively early in the filling of the tank so that the platform willnot lift or shift position due to buoyancy. Similarly, the holes willpermit water to drain from the cylinders as the tank is drained. Theholes can be ½″ diameter, for example.

With reference now to FIGS. 6-10, a second embodiment of the presentinvention is illustrated as salt platform 50. A number of elements ofsalt platform 50 are identical to that of salt platform 10 and areidentified by the same reference numeral. However, in salt platform 50,a second set of radial vertically oriented cylinders 52-62 aredistributed at uniform radial distances from the central cylinder 12.Bracing members 64 and 66 are used to secure each of the cylinders 52-62to two of the adjacent radial cylinders 14-24.

With reference to FIG. 11, a third embodiment of the present inventionis illustrated and forms salt platform 80. Again, a number of elementsof salt platform 80 are identical to that of salt platform 10 and areidentified by the same reference numeral. Salt platform 80 is providedwith a second set of radial vertically oriented cylinders 82-92 whichare spaced on the same radial lines as the cylinders 14-24. Each of thecylinders 82-92 are connected to adjacent cylinders by radial bracingmembers 94 and circumferential bracing members 96.

With reference now to FIGS. 12-14, a fourth embodiment of the presentinvention is illustrated as salt platform 100. Salt platform 100 can beseen to include a series of vertically oriented sheets 102, preferablyformed of ABS (acrylonitrile butadiene styrene) plastic. The sheets areconnected together in a spaced apart relation by a series of horizontaltubes 104, preferably formed of PVC pipe. The tubes 104 pass throughsuitably formed apertures 106 in the sheets. Holes 108 are formedthrough the tubes 104 immediately adjacent the surfaces 110 of thesheets to hold the platform together. A bolt 112 or other suitablefastener can be passed through each of the holes and secured therein, asby nut 113 so that the tube is locked in place relative to the sheets.Alternatively, fasteners such as plastic wire ties 115 can be passedthrough the holes to act in a similar manner. Other suitable fastenerswould include clips, pegs, pins, and the like.

The salt platform 100 is positioned within the water softener with theupper edges 114 of the sheets 102 supporting the salt platform. Thelower edges 116 rest on the bottom of the water softener tank.

As can be understood, the sheets can be any suitable length to fit theparticular tank used. For example, the middle sheet 118 may be longerthan the end sheets 120 if the tank is circular. Further, the loweredges 116 of the sheets can be curved in any desired configuration tobetter fit the contour of the water softener tank. Any number of sheetscan be placed side by side by simply lengthening the tubes 104 andproviding suitable mounting holes adjacent the position of each sheet.

As can be readily understood, a key part of the invention is the abilityto distribute the salt load through a plurality of vertically orientedmembers distributed relatively uniformly underneath the salt grid. Themembers need not the circular. However, PVC pipe is commonly availableand is inexpensive and forms a very effective member for use in thisapplication. The use of PVC (polyvinyl chloride) and ABS plastic havethe advantage of being very inert to brine and would be expected to havevery long service life in this application. However, any other materialcan be used to form the platform and grid which is strong enough andinert to the brine solution. An example of suitable materials include,but is not limited to, acrylics, plexiglass, fiberglass, polyethylene,polypropylene, polycarbonate, NORYL®, KEVLAR® and metal structures madeimpervious to the brine solution by resin or asphalt type coatings.

With reference now to FIGS. 15 and 16, a fifth embodiment of the presentinvention is illustrated as salt platform 200. Salt platform 200 can beseen to include a series of vertically oriented sheets 202, preferablyformed of ABS plastic. Each sheet has a series of slots 204 formed intothe sheet from one edge 206. As can be seen in FIG. 16, the sheets canbe mated to each other, with the slots of one sheet mating with theslots of another sheet, to form a rigid, self-standing platform, as seenin FIG. 15. Preferably, the slots extend somewhat over one-half of theway from edge 206 to the opposite edge so that, when the sheets aremated, the top edges of the sheets lie in the same plane to uniformlysupport the grid 34. Also, the bottom edges of the sheets should lie inthe same plane if the bottom of the tank is flat to uniformly distributethe load along the bottom of the tank.

While eight sheets are shown in FIGS. 15 and 16, it is clear that anynumber of sheets can be used. For example, two sheets can beinterconnected to form a platform. Three sheets can be mated in atriangular form to form a platform and four or more sheets can be matedto form various configurations. As will be clearly understood, the edges208 of the slots engage the surface of the mating sheet to form a rigidconstruction without the use of any fasteners whatsoever.

With reference now to FIG. 17, a grid 250 is illustrated which isintended to form part of the salt platform 10 described previously. Thegrid is preferably formed of ABS plastic, having a thickness of ⅛ or ¼inch. The typical pegboard used in previous salt platforms is usuallyavailable only in sheets of 4 foot by 8 foot, limiting the size of thegrid formed thereby to a 4 foot diameter. ABS plastic sheet is availableup to 10 feet square and grids can therefore be made larger thanprevious designs using peg board. The ABS plastic is much stronger thanpeg board and is inert in the salt water brine found in brine tanks.

The grid 250 has a circular shape and defines a border portion 252, afirst band 254 and a second band 256. The grid also defines a centralcap portion 258 and a series of radial cap portions 260-270. Theremaining portion 272 of the grid has a plurality of small holes 274drilled therethrough for water to pass and mix with salt supported onthe grid.

The grid 250 is designed to be set atop the central vertically orientedcylinder 12 and the radial vertically oriented cylinders 14-24. Theupper ends 30 of each of the cylinders need not be closed off as thegrid 250 is oriented relative to the cylinders 12-24 so that the centralcap portion 258 rests atop the upper end of the central verticallyoriented cylinder 12 and each of the radial cap portions 260-270 restatop one of the radial vertically oriented cylinders 14-24. Thus, thelabor necessary in individually installing a cap at the upper end ofeach of the cylinders is eliminated. By capping the cylinders 12-24,debris is prevented from entering the interior of the cylinders.

The use of a border portion 252, which, for a grid having a 50 inchdiameter, might be 2 inches wide, and the bands 254 and 256, which, fora 50 inch diameter grid may be about 4 inches in width, provides greatstructural strength even though the portion 272 is formed with aplurality of holes therein.

To correspond with the dimensions previously recited for the cylinders12-24, the radial cap portion 258 will be at least 6 inches in diameterif cylinder 12 is 6 inches in diameter and the radial cap portions260-270 will be at least 4 inches in diameter if the cylinders 14-24 are4 inches in diameter. Grid 250 is intended to be a direct substitute forthe grid 34 previously described.

The grid 250 has a well opening 276 formed therethrough near thecircumferential edge 278 thereof. Clearly, the grid 250 can be adaptedfor use with the salt platform 50 or salt platform 80 described abovewith sufficient cap portions to fit over the upper ends of the verticalcylinders thereof.

If desired, the grid 250 can be formed with the entire grid being likeportion 272 with holes 274 formed uniformly therethrough about theentire grid. This might be a suitable universal design for use in saltplatforms of types other than those described above.

Alternatively, a grid 280 of the type shown in FIG. 18 can be used. Grid18 incorporates border portion 252 and first and second bands 254 and256, central cap portion 258 and the well opening 276. However, noradial cap portions are provided and the remaining portion 282 betweenthe bands 254 and 256 and portions 252 and 258 are formed with uniformlydistributed holes 274 therein. Again, the use of portions 252 and 258and bands 254 and 256 provide great strength to the grid whilesufficient holes 274 are formed through the grid for it to workeffectively in the brine tank.

The well opening typically will be about 3½ inches to 6¼ inches. Gridsare typically cut to fit for new tanks. Large brine tanks have avariance in diameter and it is best to fit the grid at the shop to givea snug fit as the tank diameter varies slightly from tank to tank.Retrofitting grids in existing large brine tanks that have been inservice for some time may dictate cutting the grid to dimensions lessthan that to which the brine tank was originally designed as time andservice may have caused the tanks to be warped out of round.

Using grids of the type described herein, forming a grid for a brinetank having a diameter of 50 inches or larger is possible. This sizetank has never been able to be fitted with a grid formed of peg board inthe past because of size limitations in the material available. Becauseof variation in tank size, the border portion 252 is useful, permittingportions of the border to be cut away to fit a particular tank withoutcutting through any of the holes 274 formed in the grid.

Another variation is to form a spacer ring 290 of a diameter somewhatlarger than the diameter of the grid and an inner diameter somewhatsmaller than the inner diameter of the border portion 252. The grid 250or 280 is then cut to a diameter somewhat less than the diameter of thetank and the spacer ring is inserted in the tank on top of the grid withthe outer diameter of the spacer ring approximating the diameter of thebrine tank. The spacer ring can move about somewhat on the top of thegrid 250 or 280 and then be secured to the grid by fasteners, such aswire ties, to prevent salt from slipping between the grid edges and thewall of the brine tank. Such a spacer ring 290 is illustrated in FIG.19.

With reference now to FIGS. 20-22, a modification of the fourthembodiment of the present invention is illustrated as salt platform 300.Many elements of salt platform 300 are identical to that of saltplatform 100 and are identified by the same reference numeral. Saltplatform 300 differs from platform 100 in the use of spacer tubes 302which are slid over and concentric with the tubes 104 between each ofthe sheets 102. This eliminates the need to have bolts or ties except atthe ends of the tubes 104. The length of the spacer tubes 302 isselected to represent the desired separation between each of the sheets102 and, when the salt platform is assembled and bolts or ties 112 or115 are inserted through the holes 108 at the ends of each of the tubes104, the sheets 102 are held in the proper spacing by the spacer tubes302. The spacer tubes 302 have a larger diameter than the apertures 106formed through the sheets 102 and have a sufficiently large innerdiameter to fit over the tubes 104, preferably in a slip fit.

As illustrated in FIG. 21, the use of the spacer tubes 302 also providesan additional advantage with the top row of tubes 104. The apertures 106near the upper edge 114 of each of the sheets 102 are formedsufficiently close to the edge so that the upper surface 304 of thespacer tubes 302 proximate the upper edge are substantially coplanarwith the edges 114. This provides additional support for the grid 34laid atop the salt platform. Preferably, the apertures 106 in the toprow are formed through the sheets 102 with the distance from the upperedge of each aperture to the upper edge 114 equal to the thickness ofthe spacer tube 302.

The parts of salt platform 300, particularly spacer tubes 302, can bemade of PVC plastic. However, other materials can be used, including,but not limited to, acrylics, plexiglass, fiberglass, polyethylene,polypropylene, polycarbonate, NORYL®, KEVLAR® and metal structures madeimpervious to the brine solution by resin or asphalt type coatings.

An additional feature of salt platform 300 is shown in FIG. 23. A hole310 is formed at the end of the top row of tubes which project asignificant distance beyond the outer most sheets 102. This includes thetubes 104 passing through the center portion of the sheets 102 wherethere is a large distance from the outermost sheets 102 to the innersurface of the brine tank. The salt grid 34 is only supported by thesheets 102 and the spacer tubes 302 between the sheets, not outside thelimits of the sheets 102. These holes 310 can receive a bolt 306 whichhas a head 308 of thickness sufficient so that the grid 34 is in contactwith the head 308 of the bolt 306, which provides support for the saltgrid 34 near its edges 312 most distant from the sheets 102. Bolt 306can be of PVC, or other suitable material as noted above.

In one embodiment constructed in accordance with the teachings of thepresent invention, the head of the bolt is about one-eighth inch thickand the distance from the top of the apertures 106 to the upper edges114 is about one-eighth inch. The wall thickness of tubes 302 is alsoabout one-quarter inch.

With reference now to FIGS. 24 and 25, a ring 350 is illustrated whichis used to fit the salt grid 34 in a brine tank. The ring is splittherethrough at split 380 similar to a piston ring to allow the outercircumference of the ring to vary somewhat. The ring is made of amaterial which provides some flexibility, such as neoprene. The brinetanks in service rarely are perfectly round. Therefore, if the salt gridis formed as a circle, there will often be gaps between the edge 312 ofthe salt grid and the inner wall of the brine tank due to thisirregularity, allowing salt to fall through these gaps. The ring 350 isdesigned to accommodate this variation in brine tank wall dimensions.The ring 350 has an outer surface 352 which engages the inner wall ofthe brine tank. The ring 350 has an inner surface 354 which is formed ina series of cut back steps 356 which causes the top surface 358 of thering to be much larger than the bottom surface 360. These steps 356 forma series of ledges 362, 364, 366 and 368 which can each support the edge312 of the salt grid 34 depending upon the size of the gap between theedge of the salt grid and the interior surface of the brine tank.

During installation, the ring 350 is wrapped or fit about the edge ofthe salt grid so that the edge rests on one of the ledges 362-368. Aneffort is then made to place the ring 350 and salt grid 34 within thebrine tank. If the fit is too tight, the ring is repositioned on thesalt grid on a lower ledge until the ring 350 and salt grid 34 fitproperly in the brine tank. If there is too much of a gap still betweenthe outer surface 352 of the ring 350 and the inner wall of the brinetank, the ring 350 is repositioned on the salt grid with the edge of thesalt grid at a higher ledge. When the ring 350 is properly positioned onthe salt grid 34, there should be a snug fit between the salt grid, ring350 and inner surface of the brine tank which prevents salt on the saltgrid from inadvertently falling between the edge of the salt grid andthe inner surface of the brine tank, as well as acting to true thediameter of the brine tank to some extent.

Ring 350 can also be made of PVC or ABS plastic. However, othermaterials can be used, including, but not limited to, acrylics,plexiglass, fiberglass, polyethylene, polypropylene, polycarbonate,NORYL®, KEVLAR® and metal structures made impervious to the brinesolution by resin or asphalt type coatings.

Although several embodiments of the invention have been illustrated inthe accompanying drawings and described in the foregoing detaileddescription, it will be understood that the invention is not limited tothe embodiments disclosed, but is capable of numerous rearrangements,modifications and substitutions of parts and elements without departingfrom the spirit and scope of the invention.

What is claimed is:
 1. An apparatus, comprising: a brine tank having aninterior, an inner surface and a nominal inner diameter; a salt grid;and a ring having an outer surface engaging the inner surface of thebrine tank and an inner surface formed by a series of cut back steps,the salt grid having an edge engaging a step on the ring selected sothat the salt grid and ring fit tightly within the interior of the brinetank.
 2. The apparatus of claim 1 wherein the ring is neoprene.
 3. Theapparatus of claim 1 wherein the ring is split.
 4. The apparatus ofclaim 1 wherein the salt grid is ABS plastic.
 5. The apparatus of claim1 in the ring has a center, each of said cut back steps of said seriesof cut back steps being a different radial distance from the center. 6.A spacing apparatus for fitting a salt grid within the interior of abrine tank, the brine tank having an inner surface and a nominal innerdiameter, comprising: a ring having an outer surface engaging an innersurface of a brine tank and an inner surface formed by a series of cutback steps, a salt grid having an edge engaging a step on the ringselected so that the salt grid and ring fit tightly within the interiorof the brine tank.
 7. The apparatus of claim 6 wherein the ring isneoprene.
 8. The apparatus of claim 6 wherein the ring is split.
 9. Theapparatus of claim 6 wherein the salt grid is ABS plastic.
 10. Thespacing apparatus of claim 6 wherein the ring has a center, each of saidcut back steps at a different radial distance from the center.
 11. Amethod for fitting a salt grid within the interior of a brine tank, thebrine tank having an inner surface and a nominal inner diameter,comprising the steps of: fitting a ring having an outer surface and aninner surface formed by a series of cut back steps about an edge of asalt grid so that the edge of the salt grid rests on a ledge formedbetween an adjacent pair of said steps; and placing the ring and saltgrid within the brine tank to determine if the ring and salt grid are asnug fit in the brine tank.
 12. The method of claim 11 furthercomprising the step of repeating the step of fitting the ring on thesalt grid at a different ledge between an adjacent pair of said stepsand placing the ring and salt grid within the brine tank until the ringand salt grid are a snug fit within the brine tank.
 13. The method ofclaim 11 further comprising the step of expanding the ring at a splittherein to fit the ring over the edge of the salt grid.